1. Field of the Invention
The present invention generally relates to an information-processing apparatus and method, and more particularly to an information-processing apparatus and method which provides a client with a function that needs exclusive access control.
2. Description of the Related Art
In recent years, in a system in which a plurality of clients and an information-processing apparatus are connected together via a network, the functions of the information-processing apparatus are often shared among the plurality of clients. When a function request for using a certain function of the apparatus is received from a particular client, the apparatus starts the transaction according to the function request, and allows the particular client to use that function.
The transaction herein is a processing range or processing unit having a significant meaning, and it means a series of indivisible processing steps that needs exclusive access control in which the exclusion of the intervention from other clients etc. is carried out.
With respect to this, there are various examples of the intervention, including the setting change request, the updating request of shared information, and the acquisition request of shared information, which are sent from other clients, and the setting change request, the power down request, the power-saving mode  shift request, and the reboot request, which are inputted from the operation panel of the information-processing apparatus.
For example, when an updating request of 200-page document data is received from the user, a series of processing steps to perform the updating or writing of the 200-page document data to the shared information is called the transaction. In addition, even in a case when an updating request of 200-page document data is received from the user and the information-processing apparatus carries out the updating or writing of the document data to the shared information one page at a time, a series of processing steps to perform the updating or writing of the 200-page document data to the shared information is the transaction.
The information-processing apparatus generally finishes the transaction by the time-out when a predetermined time-out period has elapsed after the last function request was received from the client.
Japanese Laid-Open Patent Application No. 7-064836 discloses a computer system in which the user explicitly notifies to the server the start/end of the transaction.
Moreover, Japanese Laid-Open Patent Application No. 2001-155012 discloses a computer system in which the functions within the network are shared.
In the conventional information-processing apparatus, if a function request from a client is received again after the transaction is started, the transaction is extended. However, the  conventional information-processing apparatus is not provided to manage the transactions in accordance with the function requests received from the respective clients. Hence, every time the function request from any client is received again since the transaction is started, the transaction is extended.
For this reason, the conventional information-processing apparatus takes a relatively long time to finish the transaction by the time-out, and has the difficulty in managing the transaction efficiently.
Moreover, the conventional information-processing apparatus continues to reject the intervention by other clients until the transaction is finished by the time-out, and has the problem that it is difficult to quickly handle the intervention of the power down request etc. from other clients.
Furthermore, since the conventional information-processing apparatus is not provided to manage the transactions in accordance with the function requests received from the respective clients, there is the problem that the client is unable to control the transaction so as to be ended before the time-out period expires.